The present invention relates generally to a magnetic tape cassette particularly adapted for thrust-loading. More specifically, the invention relates to a magnetic tape cassette having tape reel assemblies each with a reel hub which floats axially and cooperates with a center core of the respective reel assembly for rotation therewith.
In general, a magnetic tape cassette has a pair of tape reel assemblies with central through openings or bores for receiving a reel shaft of a recording and reproducing apparatus, such as, a tape player unit. The through openings in the tape reel assemblies have radially opening grooves or recesses. The reel shafts have a plurality of radial extensions or drive lugs which conform to the radial recesses or grooves in the through openings. Engagement between the extensions and the grooves rotatably couples of the tape reels with the respective reel shaft for recording and reproducing of the data.
In the magnetic tape cassette constructed as set forth above, the magnetic tape tends to be stressed through the tape reels upon loading. Such stress is apt to damage the magnetic tape and to affect performance and/or quality of recording and reproduction.
In addition, in such typical magnetic tape cassettes, it is necessary to insert the reel shaft into the through opening deep enough to establish engagement between the extensions and the grooves. Conventionally, in order to obtain satisfactory engagement between the extensions and grooves, it has been necessary to insert the reel shaft to a depth of at least half of the overall axial length of the through openings. This type of tape cassette cannot be loaded in a player unit with a tape-loading mechanism of the so-called thrust-loading type. In thrust-loading, the reel shaft is inserted into the openings or bore of the respective tape reel to a relatively shallow extent. On the other hand, thrust-loading of tape cassettes is known to be advantageous in that it requires less vertical clearance for loading the tape.
In order to form a more compact, in particular a thinner tape player unit, it is desirable to employ a thrust-loading system. Thus, a magnetic tape cassette suitable for thrust-loading is required.